Environmental chemicals may hurt chances of pregnancy

Exposure to common chemicals such as polychlorinated biphenyls (PCBs) may hamper a couple’s efforts to conceive a child, a new study shows. “This suggests that some environmental chemicals might be important for human reproduction, specifically the time it takes couples to get pregnant,” said lead researcher Germaine Buck Louis, director of the division of epidemiology, statistics and prevention research at the Eunice Kennedy Shriver National Institute of Child Health and Human Development in Rockville, Md. Despite being banned, PCBs and other similar chemicals are still present in the environment. “The chemicals in this paper are commonly referred to as persistent environmental chemical compounds, meaning that when they get into the environment they don’t break down,” Louis explained. Exposure often originates in the family kitchen, where processed and high-fat foods harbor the compounds. Heating plastic containers in the microwave oven also ups the risk of exposure, experts say. “Humans are exposed largely through their diet,” Louis said. “It takes a long time for these chemicals to clear from the body, but the key is to try to minimize new exposure.” One way to do that is to trim the fat from fish and meat, which is where some of these chemicals are absorbed, the researchers noted. For the study, Louis’ team collected data on 501 couples who gave blood samples so the researchers could measure the levels of these chemicals. In addition, the women kept a record of their menstrual cycles and the results of home pregnancy tests. Over a year of follow-up, they found as the levels of chemicals increased, the odds of getting pregnant decreased. For women exposed to PCBs and the perfluorchemical known as perfluorooctane sulfonamide, the odds dropped by 18% to 21%. Perfluorooctane sulfonamide belongs to a class of chemicals known as perfluoroalkyls, which have been used in fire-fighting foams. For men, the odds dropped 17% to 29% for those exposed to PCBs and DDE, which is produced by degrading of the pesticide DDT. Although DDT was banned in the United States, it is still used in some countries, the researchers noted.